This invention relates to a method of producing freeze-dried, cooked beef steak which is tender when rehydrated and which rehydrates rapidly to the extent of reabsorbing within 10 minutes at least about 95 percent of the moisture which it contained prior to being freeze-dried and of reabsorbing within 2 minutes sufficient moisture to make the steak acceptable (at least about 90 percent of the moisture which it contained prior to being freeze-dried).
The production of freeze-dried, cooked beef steak which upon being rehydrated would be acceptably tender as well as desirably flavored compared to a freshly cooked beef steak from the same muscle of a given beef animal has been a problem of long standing, particularly in the production of rations for the military. Freeze drying is a well-known procedure for preserving many types of foods both in the cooked and the raw state. However, most foods, when freeze dried, become quite board-like, brittle, and unsuitable for consumption without prior rehydration or reconstitution. Beef steak is one such food, and in addition, since it is made primarily of proteinaceous muscle fibers, it quite often is very tough when cooked, freeze dried, and thereafter rehydrated.
Various procedures have been employed to tenderize beef steak, both for immediate consumption and for preservation until some later time, as by freezing, freeze drying, or other means or methods. None of these procedures has succeeded in producing freeze-dried, cooked beef steak which upon rehydration would have good texture, especially tenderness, and which would be rehydratable within a short period of time (preferably appreciably less than ten minutes) so as to restore the steak to a highly acceptable state all-around and particularly with respect to tenderness since that is one of the most important attributes of beef steak and one which determines in great measure the value of a piece of meat. One of the more frequently employed tenderizing methods applied to meat involves mechanical rupturing of the muscle fibers, e.g. by kniving or otherwise. Another method involves treatment of the meat with proteolytic enzymes to partially degrade the protein of the meat and particularly, insofar as possible, to degrade the connective tissue since an overabundance of such tissue seems to contribute a great deal to making meat tough. Yet another procedure that has been previously found to aid in reducing the degree of toughness of various meats, fish, or other largely muscular foods involves soaking the meat in a solution of a phosphate or injecting the meat with, i.e. pumping into the meat, a solution, preferably aqueous, of a phosphate, such as sodium tripolyphosphate, sodium pyrophosphate, one of the several sodium orthophosphates, or some other phosphate, usually in the form of a sodium salt or mixture of sodium salts, and sometimes in combination with sodium chloride. None of these procedures used alone with cooked beef steak results in a freeze dried steak which rehydrates very rapidly and substantially completely within less than ten minutes, and preferably within about two minutes, and which is acceptable in tenderness as well as in other organoleptic characteristics immediately following such short-term rehydration or reconstitution as does the process of the present invention.
Mechanical tenderization of meat is disclosed in United States Pat. Nos. 3,256,801; 3,535,734; 3,583,025; and 3,842,464. Chemical solution tenderization of meat or fish of various types is disclosed in U.S. Pat. Nos. 2,140,781; 2,999,019; 3,207,608; 3,620,767; and 3,875,313. There are also United States patents relating to the curing of meats using aqueous solutions of various salts as curing agents, particularly for pork, some of which disclose the incorporation of a phosphate salt or mixture of such salts or mixtures thereof with sodium chloride or other non-phosphate salts. Representative of such patents are U.S. Pat. Nos. 2,903,366 and 3,028,246. Phosphate solutions have also been disclosed for use in preventing or reducing fluid exudation from small cuts of meat, as in U.S. Pat. No. 3,049,428.
An object of the present invention is to provide a freeze-dried, cooked beef steak which, when treated with water to rehydrate it, regains sufficient moisture within a short period of time, such as no more than ten minutes, to make it acceptable, and which is very tender in the rehydrated state while retaining good all-around organoleptic qualities and to provide a method of producing such a freeze-dried, cooked beef steak product.
Other objects and advantages will become apparent from the following description of the invention.